This invention relates generally to a two-stoke internal combustion engine which does not have a compression process as part of its operating cycle; more specifically, this invention relates to an engine which uses an innovatively timed sequence of injecting and igniting fuel and oxidant to achieve high operating efficiency, high torque values, and low thermal loading for engine components. The engine will operate efficiently with a number of different fuel/oxidant combinations and it can be utilized in both stationary and mobile applications.
Some of the more important applications for the engine described in this specification exist in the renewable energy field. During the past few decades, there have been important advances in technologies for cost-effectively converting various types of renewable energy (solar, wind, tidal, etc.) into the kinds of energy required by modern societies. In spite of these advances, utilization of renewable resources is still very limited. This is primarily because of strong hourly, daily, and seasonal variations in the availability of most types of renewable energy. Modern societies require steady, uninterrupted supplies of energy, but energy from renewable sources is not always available when needed. Clearly, efficient energy storage and reconversion technologies must be developed if renewable energy is to become a significant factor in meeting global energy needs.
Intermittent availability is especially problematic for the electricity generated from renewable resources. This is because technologies for direct storage of electrical energy (capacitors, super-conducting inductors, batteries, etc.) cannot be economically scaled to meet the demands of large energy markets. In addition, previously proposed technologies for indirect storage of electricity (technologies that transform electricity into more easily stored energy forms) have been shown to be inefficient and expensive, and in some cases, applicable only in very specific geographic locations.
Among the more thoroughly studied indirect approaches for storing and subsequently utilizing electricity are technologies that are commonly referred to as electrolysis-storage-reconversion (ESR) processes. Basically, these processes consist of three main steps: (1) electrolysis of a chemical compound to produce chemical energy in the form of a combustible fuel, (2) combustion of the fuel in a heat engine to produce mechanical energy, and (3) utilization of the mechanical energy to perform a desired task, such as driving an electrical generator or powering a transportation vehicle. A specific example of this general procedure is the basis for what is sometimes referred to as the hydrogen economy, with the electrolyzed chemical compound being water, the combustible fuel being hydrogen, and the heat engine being some sort of internal combustion engine. The greatest barrier to implementing the hydrogen economy on a global scale is the overall inefficiency of previously proposed ESR processes—and the greatest energy losses for these ESR processes occur in the heat engines used in the reconversion step.
The primary objective of this invention is to offer a low-cost, high-performance internal combustion engine that uses fuel—and possibly oxidant—that is generated by an electrolysis process. The innovative thermodynamic cycle by which the presently proposed engine operates can be carried out with any one of a number of different fuel/oxidant combinations. However, the embodiment of the present invention which is anticipated to give optimal performance is an engine which uses high-pressure hydrogen gas as the fuel and high-pressure oxygen gas as the oxidant, both of which can be provided by the electrolysis of water. Thus, the engine disclosed herein offers technology improvements that make an important ESR process less costly and more efficient. This engine, when coupled with existing high-efficiency electrolysis techniques and newly-developed gas storage capabilities, will transform renewable energy resources into reliable and economically practicable energy supplies that are capable of meeting the demands of large and small energy markets all over the world.